1. Field
The present invention relates to a hydraulic pressure fluid regulator and more particularly to a regulator for use in providing a controlled pressure level to a fluid pressure actuated device.
2. Prior Art
The prior art includes various controllers dealing particularly with fuel regulator systems and spool valve type devices.
Included in the prior art is a fuel regulator cooperating with a charge forming apparatus as shown in U.S. Pat. No. 3,977,388 of a type in which excess fuel is recirculated from the charge forming apparatus and maintains a stable pressure and air fuel ratio. Another embodiment teaches an electronically controlled transducer for varying air pressure in air fuel ratios, which transducer utilizes a solenoid operator to control flow to a reference pressure chamber. The use of spool valves is known throughout the valve art. This is illustrated in "Hydraulic Control Systems", H. E. Merritt, John Wiley and Sons 1967, page 331 and 332 where a pressure control valve system is shown for pressure relief. Specifically this illustration shows the use of an orifice and a spring loaded pilot valve to relieve pressure in a chamber.
U.S. Pat. No. 4,436,489 (Zangenberg) discloses a valve means with a bore therein for use in a control device for a liquid pump. However, this device regulates the pump not the flow therefrom which flow passes directly to a fluid motor.
A pressure fluid circuit for an automatic transmission is taught in U.S. Pat. No. 3,678,952 (Nishimura). This patent teaches a line pressure circuit monitoring pump discharge pressure which is controlled by a valve connected to a governor circuit having a leak valve operable by centrifugal force corresponding to transmission shaft output speed. The valve provides flow resistance as a function of pressure in the governor circuit to sustain a minimum pressure required for transmission clutch operation.
A means for controlling hydraulic pressure in an automobile pressure application is known in the art as a proportional solenoid (VFS to regulate pressure to clutches). This device utilizes an electromagnetically movable armature in contact with a spool valve. The armature controls the position of the spool valve to thereby open fluid flow to an operating mechanism at the output pressure. This particular device is accurate, but requires extreme care in manufacture due to the close tolerances associated with the position of such armature and spool valve, and it utilizes up to 1.0 amperes current to control the operation of the spool valve.